The present invention relates to a receiver apparatus used in a mobile communication system such as a portable telephone, and in particular, to a receiver apparatus with reduced power consumption.
The services originally provided to users by a mobile communication system have been primarily an audio communication, however, recently the function has been progressed to a higher degree in which a data communication is capable. Corresponding to this, large parts consuming much power such as an FM sound source and a large type display device have been mounted on a terminal. Because of this, it has been requested to further reduce the power consumption of the parts constituting the terminal. The receiver section of the direct conversion system is described, for example, in Behazad Razavi “RF MICROELECTRONICS”, PRENTICE HALL PTR, pp. 122–129, 138–144, 146–147 and 209–231, or JP-A-10-256930 corresponding to U.S. Pat. No. 6,339,711 and U.S. patent application publication No. 20,020,032,009.